Investigating the effects of conventional and unconventional edible parts of red beet (Beta vulgaris L.) on target bacterial groups and metabolic activity of human colonic microbiota to produce novel and sustainable prebiotic ingredients

This study investigated the effects of freeze-dried red beet root (FDBR) and freeze-dried red beet stem and leaves (FDBSL) on target bacterial groups and metabolic activity of human colonic microbiota in vitro. The capability of FDBR and FDBSL to cause alterations in the relative abundance of different selected bacterial groups found as part of human intestinal microbiota, as well as in pH values, sugar, short-chain fatty acid, phenolic compounds, and antioxidant capacity were evaluated during 48 h of in vitro colonic fermentation. FDBR and FDBSL were submitted to simulated gastrointestinal digestion and freeze-dried prior to use in colonic fermentation. FDBR and FDBSL overall increased the relative abundance of Lactobacillus spp./Enterococcus spp. (3.64-7.60%) and Bifidobacterium spp. (2.76-5.78%) and decreased the relative abundance of Bacteroides spp./Prevotella spp. (9.56-4.18%), Clostridium histolyticum (1.62-1.15%), and Eubacterium rectale/Clostridium coccoides (2.33-1.49%) during 48 h of colonic fermentation. FDBR and FDBSL had high positive prebiotic indexes (>3.61) during colonic fermentation, indicating selective stimulatory effects on beneficial intestinal bacterial groups. FDBR and FDBSL increased the metabolic activity of human colonic microbiota, evidenced by decreased pH, sugar consumption, short-chain fatty acid production, alterations in phenolic compound contents, and maintenance of high antioxidant capacity during colonic fermentation. The results indicate that FDBR and FDBSL could induce beneficial alterations in the composition and metabolic activity of human intestinal microbiota, as well as that conventional and unconventional red beet edible parts are candidates to use as novel and sustainable prebiotic ingredients.

Automated summary

This study investigated the effects of freeze-dried red beet root and stem and leaves on the human colonic microbiota in vitro. The results showed that both red beet root and stem and leaves increased the abundance of beneficial bacterial groups and decreased the abundance of harmful bacterial groups during colonic fermentation. Additionally, they also increased the metabolic activity and antioxidant capacity of the human colonic microbiota. These findings suggest that red beet root and stem and leaves could be used as novel and sustainable prebiotic ingredients.